How to Determine Bending Radius

Our customers occasionally ask us: “How tight can I get away with bending this cable?” when installing wire and cable in trays with curves, in ducts, around building corners or around sheaves. Bending radius information provided by the NEC (National Electric Code) and the Insulated Cable Engineers Association (ICEA) allows us to provide the following simple table to use as a guideline.

To use the table, obtain the cable diameter from either the manufacturer or by measuring the cable if you already have it. Then, simply multiply that diameter by the factor on the right side of the table.